1. Field of the Invention
This invention relates to resin impregnated composite wood products and to the method of making same utilizing most sources of wood such as logs, tops of logs remaining after a logging operation on land being cleared, scrap wood from saw mills, wood from buildings being destroyed and other wood sources where the wood usually ends up rotting on the land or in land fills. Environmental concerns and good business practices require the use of procedures and methods to eliminate the waste, to conserve natural wood resources and to promote the general welfare of this country in order to maintain a competitive position in wood products throughout the world.
2. Description of the Prior Art
Various attempts have been made to utilize laminated wood structures with varying degrees of success. U.S. Pat. No. 1,465,383 of Frank J. Walsh entitled "Composite Lumber" utilizes strips of soft wood of approximately one-fourth inch thick, cut to length and width. The strips are arranged in layers, with the strips of one layer arranged at a ninety degree angle to the strips in the adjacent layers. Cement is employed for the purpose of securing the layers together and is not used to saturate or soak into the entire mass of the wood for the purpose of filling the pores thereof with cement as in the present invention. Walsh permanently deforms the cells of the wood with pressure so as to bring the fibers themselves into permanent frictional contact and engagement with each other rather than to fill the cells with cement.
U.S. Pat. No. 4,255,477 of John A. Homan, entitled "Artificial Board of Lumber," teaches that an artificial lumber board having superior strength can be made by providing a plurality of boat-shaped wood strips, each wood strip being elongated defining first and second ends with tapered tip portions formed adjacent each said first and second ends reduced in thickness relative to a medial portion of the wood strip. An adhesive coating is carried by each wood strip and the wood strips are compressed in the artificial board aligned generally longitudinally extending in the board. The tapered tip portions terminate at a substantial point enabling the compressed wood strips to join and fit one another generally at a point contact reducing the presence of void spaces in the artificial board.
U.S. Pat. No. 4,968,549 of Shin Smimizu, et al entitled "Laminated Material Made of Annual Legnocellulosic Stalks" discloses and claims a laminated board made from legnocellulosic stalk, with the board having a plurality of sheets which are stacked and bonded with a resin adhesive.
U.S. Pat. No. 5,525,394 of John T. Clarke, et al entitled "Oriented Strand Board-Fiberboard Composite Structure and Method of Making the Same" discloses an oriented strand board-fiberboard composite structure having multiple wood layers.
Such laminated materials are used for various building materials, such as heat insulating materials, building material for fixture, sound absorbing materials, and furniture materials or structural building materials. Building materials other than plywood and veneer include wood based materials such as particle board and fiberboard.
Particle board is made by combining wood chips and a synthetic resin adhesive mixture with heat and pressure. Fiberboard is made by compressing wood and other vegetable fibers. Particle board and fiberboard do not suffer from aeolotropy in practical use and lack the shortcomings of natural materials, such as knots, rot, dimensional distortion, and warping. Furthermore, one can select the desired specific gravity, thickness, and size of these boards according to use.
The main material of the above-mentioned wood based materials is natural wood, the supply is limited and may not be sufficient to meet demand in the future. Thus, there is a fear that wood based materials will become expensive unless substitute composite wood products are found utilizing scrap wood and which can serve as a substitute for natural wood based materials.